Figure F6. A. Natural Spectral Gamma Ray Tool logging data and inductively coupled plasma–mass spectrometry (ICP-MS) analyses of discrete samples to obtain an estimate for the uranium content of the oceanic crust (from Kelley et al., 2003). B. Pb/U vs. Th/U in arc basaltic lavas (all ICP-MS data). Triangles = Honshu (Gust et al., 1995), squares = Aleutians (Plank, 2005), circles = Marianas (Elliott et al., 1997), diamonds = Mariana backarc (Pearce et al., 2005). Thin black lines are RMA linear regressions through data.Thick black line illustrates the difference between bulk altered oceanic crust (AOC) (based on ODP Site 801 composites) and the AOC-derived fluid, demonstrating a common enrichment in Pb over U in the fluid component that recycles to volcanic arcs (figure from Kelley et al., 2005).

Figure F6. A. Natural Spectral Gamma Ray Tool logging data and inductively coupled plasma–mass spectrometry (ICP-MS) analyses of discrete samples to obtain an estimate for the uranium content of the oceanic crust (from Kelley et al., 2003). B. Pb/U vs. Th/U in arc basaltic lavas (all ICP-MS data). Triangles = Honshu (Gust et al., 1995), squares = Aleutians (Plank, 2005), circles = Marianas (Elliott et al., 1997), diamonds = Mariana backarc (Pearce et al., 2005). Thin black lines are RMA linear regressions through data.Thick black line illustrates the difference between bulk altered oceanic crust (AOC) (based on ODP Site 801 composites) and the AOC-derived fluid, demonstrating a common enrichment in Pb over U in the fluid component that recycles to volcanic arcs (figure from Kelley et al., 2005).